If you’ve ever shopped for a sun shirt, you may be wondering what all this talk about UPF is. So welcome to UPF 101.
SPF vs UPF: What’s the Difference?
Both standards refer to sun protection, but with different kinds of products.
“Ultraviolet Protection Factor is a standard that measures the effectiveness of sun protective fabrics,” says Corey Simpson, Patagonia’s communication manager of product and sport communities. “It is a specific standard for fabrics. SPF (Sun Protection Factor) is a standard specifically for sunscreens.”
It’s easy to get those similar acronyms mixed up, but it’s crucial to distinguish between the two. In a paper for the Skin Cancer Foundation, researchers Peter Gies and Alan McLennan point out that a UPF rating denotes how much ultraviolet light penetrates through a fabric. And unlike SPF ratings, which only measure for harmful UVB light, UPF ratings consider UVA and UVB, both of which can contribute to skin cancer.
Unlike SPF ratings, which only measure for harmful UVB light, UPF ratings consider UVA and UVB.